Sharpening Knives

[scubadoo97]

I like the EP but still have the original EP stones which require soaking. With my glass stones its just splash and go so I can touch up my stones in the time it takes to soak

These days with so my after market stones cut to fit the edge pro you have a lot to choose from

[patrickamory]

With full respect to the professionals who really do wear down their edges, and the hobbyists who enjoy sharpening for its own sake (and I totally get the sexiness) - I agree with weinoo that what is usually needed for most home cooks is honing - restoring the edge.

[Porthos]

I like the EP but still have the original EP stones which require soaking. With my glass stones its just splash and go so I can touch up my stones in the time it takes to soak

These days with so my after market stones cut to fit the edge pro you have a lot to choose from

The EP that I have simply has a small squirt bottle for wetting the stones. Soaking to get started would slow me down but I would still use it.

[scubadoo97]

I like the EP but still have the original EP stones which require soaking. With my glass stones its just splash and go so I can touch up my stones in the time it takes to soak

These days with so my after market stones cut to fit the edge pro you have a lot to choose from

The EP that I have simply has a small squirt bottle for wetting the stones. Soaking to get started would slow me down but I would still use it.

The squirt bottle is to wash off the swarf while sharpening. They are suppose to be soaked prior to use

[gdenby]

As I started doing more cooking, I realized my knives were fairly dull, despite steeling them w. every use. I tried to improve them w. hand sharpening. I had previously only sharpened smaller carving knives and gouges. I found that I could not manually keep anything like a consistent edge over the 8"+ of a chefs knife or slicer. Ended up w. an Edge Pro Apex. Pretty happy w. it.

I have started touching blades up w. fine grit papers on glass. Perhaps if I had started 10 or 20 years earlier, I might feel confident working by hand, but the mechanical assist lets me keep a decent edge on my knives.

A story about machine sharpeners. My wife and I received a very nice Sabatier/Hoffritz chef's knife as a wedding present. I was so impressed with it, I bought a similar one for my mother, who was a spectacular home cook. Hosted parties w. 30 people several times a year, had 2 stoves, 2 'fridges and a freezer, etc. She bought a mechanical sharpener to keep the Sabatier keen. I understand the home models now can be decent, but not back then. I recall the rasping grinding sound as she pulled the blade thru. After she died, and my father moved from the house, among the things I gathered from her utensils was the Sabatier. Sigh. It was in sad shape.

I've been re-profiling it. When new, it was advertised as an 8" blade. It is now 7.5" The long tapering point had been ground away to a blunt curve, and at least an 1/8" of the blade had been hollowed away towards the heel. I've spent hours w. a coarse diamond plate, plus the EdgePro coarse stone and almost have it flat again.

[Porthos]

The squirt bottle is to wash off the swarf while sharpening. They are suppose to be soaked prior to use

FWIW: Neither the instruction booklet that came with my EP or the instructional DVD call for soaking the stones first. The manual calls for wetting the stone with the water bottle after it has been installed on the EP. I'm not sure what the difference is between our EPs would be.

[dcarch]

When you put a drop of water on the stone, and the water disappears into the stone, that stone will need to be soaked.

Otherwise not.

dcarch

[Porthos]

I decided to send an email to EdgePro asking about soaking the stones. I'll let you know what the response is.

[rotuts]

all you need to so is flood the stones, one way or another. soak them for 30 secs while you set up works fine.

use a little liq. detergent in the spritzer bottle and keep the stones really really wet. makes for a very smooth operation.

[scubadoo97]

It's been a few years since I purchased my EP and at that time Ben advised soaking. It was also the general opinion of all the sharpening folks at foodieforum and knifeforum.

I think what Dcarch said is correct

[rotuts]

30 seconds they are thin not like a full sized water stone.

[Dakki]

A story about machine sharpeners. My wife and I received a very nice Sabatier/Hoffritz chef's knife as a wedding present. I was so impressed with it, I bought a similar one for my mother, who was a spectacular home cook. Hosted parties w. 30 people several times a year, had 2 stoves, 2 'fridges and a freezer, etc. She bought a mechanical sharpener to keep the Sabatier keen. I understand the home models now can be decent, but not back then. I recall the rasping grinding sound as she pulled the blade thru. After she died, and my father moved from the house, among the things I gathered from her utensils was the Sabatier. Sigh. It was in sad shape.

I've been re-profiling it. When new, it was advertised as an 8" blade. It is now 7.5" The long tapering point had been ground away to a blunt curve, and at least an 1/8" of the blade had been hollowed away towards the heel. I've spent hours w. a coarse diamond plate, plus the EdgePro coarse stone and almost have it flat again.

If it's like my Sab (it might not be, the Sabatier brand is a designation of origin, not a single factory's brand) it has a bolster that gets in the way of straightening off that hollow. I suggest taking it to a machining job shop to have them grind it off. If they can't/won't do it "wet" (liquid cooled), find another job shop.

[scubadoo97]

It hasn't been mentioned but flattening your stones is also vital to achieving a great edge. It doesn't take long to develop a little dishing

[rotuts]

Ive solved this problem by getting a second blank of each grit I use. i label the back with a sharpie 1 & 2, then 3 & 4 for the second, at the ends on the steel side.

after a sharpening session, I rub the two blanks of the same grit under running water until most if not all of the metal has been removed. its very quick. the blanks stay flat.

then the next time i use the I put the next number of that particular blank at the top. you get very even wear that way and a clean flat blank each time.

flat makes a big difference, as does a light hand while 'planing' the knife.

[Dakki]

It hasn't been mentioned but flattening your stones is also vital to achieving a great edge. It doesn't take long to develop a little dishing

Heh, actually I mentioned that (and the proper way of flattening) in my first post.

[gdenby]

I've been re-profiling it. When new, it was advertised as an 8" blade. It is now 7.5" The long tapering point had been ground away to a blunt curve, and at least an 1/8" of the blade had been hollowed away towards the heel. I've spent hours w. a coarse diamond plate, plus the EdgePro coarse stone and almost have it flat again.

If it's like my Sab (it might not be, the Sabatier brand is a designation of origin, not a single factory's brand) it has a bolster that gets in the way of straightening off that hollow. I suggest taking it to a machining job shop to have them grind it off. If they can't/won't do it "wet" (liquid cooled), find another job shop.

Yes, from what I've read, even in the mid 1970s, Sabatier was a conglomerate. As I mentioned, the knife we were given also had Hoffritz on the blade. For stainless, it takes a remarkable edge, tho' somewhat brittle. I maintain it at 18 degrees per side. What I bought for my Mom came from the same shop, and the knife looked the same, tho' it was carbon and not stainless.

Working on the blade is mostly for nostalgic purposes. And, waste not, want not. The steel might be better than average, so I've slowly ground away the heel manually without over heating the metal.

[dcarch]

I have a couple of blades made of D-2 steel, which I think is a good steel for someone like me, who doesn't treat knifes with tender loving care.

D-2 is kind of a semi-stainless and is heat hardened, in other words, it is not easy to damaged the edge by overheating.

dcarch

[Dakki]

That doesn't matter. Temper will be screwed by heat on any heat treated steel part (and I think work-hardened and precipitation-hardened knives are probably pretty rare).

I think you were thinking of austenitic stainless or maybe hot hard steels (H series and similar).

[scubadoo97]

It hasn't been mentioned but flattening your stones is also vital to achieving a great edge. It doesn't take long to develop a little dishing

Heh, actually I mentioned that (and the proper way of flattening) in my first post.

And so you did. Sorry for missing it

[Dakki]

It's fine dude, I don't think anyone actually reads my posts except the mods.

[dcarch]

D-2 is a tool steel, I think it can take a lot of heat abuse, These D steels retain their hardness up to a temperature of 425 °C (797 °F). I agree, at some point, heat changes metal quality.

dcarch

Edited September 19, 2013 by dcarch (log)

[Dakki]

There's tool steels and there's tool steels. W series is just a high-quality carbon steel.

D2 is specifically formulated for wear resistance, not hot work. For that, you want one of the hot-hard steels.

How much heat is "a lot" is entirely subjective, but knifemaker Roman Landes has done a great deal of research on the topic of edge "burning" on power tools and gadgets. I don't recall the exact temps reached or the precise degree of damage done, but his conclusion can summed up as "just don't."

[Dakki]

But don't take my word for it: Herr Landes discusses it with others in this thread.

Relevant quote:

A normal steel block apx. 2"x2"x4" that had a large number of highly sensitive thermocouples integrated in the surface.
The block was slit dry by hand over a 1000grit grinding paper.
The peak temps measured, walked up to 2000°C for split seconds in the very surface (some microns).
Of course the block did not melt since the volume fraction of induced heat was to tiny to affect such a large solid piece of steel.
But the effect was there and proofen.
In a edge we just talk about some microns of material, here the effect is solid an clear.

[dcarch]

I certainly would not dispute the expert in their finding that "The peak temps measured, walked up to 2000°C for split seconds in the very surface (some microns)."

My question would be how does heat effects the metal when it is only microns thick. Is it possible that it actually enhances the hardness of the metal? The rapid cooling by the large high heat conductance of the metal underneath is like oil quenching hardening.

I don't know if such incredibly small amount of heat can have any effect. It is like when you comb you hair with a plastic comb, you can actually generate a million volts of electricity.

dcarch

[Dakki]

I certainly would not dispute the expert in their finding that "The peak temps measured, walked up to 2000°C for split seconds in the very surface (some microns)."

My question would be how does heat effects the metal when it is only microns thick. Is it possible that it actually enhances the hardness of the metal? The rapid cooling by the large high heat conductance of the metal underneath is like oil quenching hardening.

I don't know if such incredibly small amount of heat can have any effect. It is like when you comb you hair with a plastic comb, you can actually generate a million volts of electricity.

dcarch

That conclusion is not supported by Landes' book, or so I'm told. Unfortunately I don't speak German. My secondhand understanding is that empirical experiments have pretty conclusively proven decarburizing and other ill effects occur in knife edges subjected to uncooled power grinding, both bench grinder and belt grinder types, even with "commonsense" tricks such as soaking the blade in ice water beforehand, etc.

Short version: There seems to be at least some evidence that the practice is bad for knife steel, plenty of evidence that it just plain removes too much metal too darn fast, and no discernible upside unless you're charging for the service. I for one am avoiding it.